Sidewall sampler bullet



Aug. 25, 1959 w. E. I INN SIDEWALL SAMPLER BULLET Filed Sept. 30, 1957 3 Sheets-Sheet 1 INVENTOR WILL/AM E. L/NN Aug. 25, 1959 w. E. 1NN

sIDEwALL SAMPLER BULLET ets-Sheet 2 5 She Filed Sept. 30, 1957 vim.

INVENTOR WILL/AM E. LIM/Vl Aug. 25, 1959 w. E. LINN SIDEwALL SAMPLER BULLET 3 Sheets-Sheet 3 Filed Sept. 50, 1957 2f INVENTOR t W/LL/AM E. L/NN Unite tates atent SIDEWALL SAMPLER BULLET William E. Linn, Denver, Colo., assigner, by mesne assignments, to California Research Corporation, San Francisco, Calif., a `corporation of Delaware Application September `30, 1957, Serial No. 687,'195

6 Claims. (Cl. Z55-1.4)

This invention relates to a means for obtaining geo logical samples from the various strata penetrated by a well bore and to a projectile or bullet for use in a sampler gun of the type used to take samples of earth formations from the side Walls of a well bore. The invention relates more particularly to a projectile or bullet for the purpose described provided with means for retaining samples of loose or friable strata from which side wall samples are desired.

The stratigraphy of the earth formations penetrated by a well bore is frequently determined and evaluated through the use of several logging devices that may be lowered into the Well bore. Unfortunately, many of these logging devices and the procedures used in operating the logging devices provide inconclusive determinations of the actual geology of the formations being logged. For example, in electric logs low resistivity sands and silty sands which are hardly discernible on the log have `been known to make excellent producers, Whereas, on the other hand, some sands whose log indicates characteristics of good oil or gas sands have produced little or nothing. Because of problems of the foregoing nature, and because of the desire to have actual Samples of the side walls of the Well bore for more accurate evaluation, it has become the frequent practice to take samples of the earth formations penetrated by a Well bore. One method of performing the foregoing practice is to lower into the well bore a sampler gun having a suitable plurality of sample receiving projectiles. The projectiles are forced into the `side Walls of the well bore to enclose a Sample thereof. The projectiles are leashed to the sampler gun so that as the gun is moved within the well bore the projectiles are removed from the side wall to be raised to the well head.

Certain geological formations, known to be important producers of petroleum crudes, pose a dii'licult problem to presently used prior art side Wall sampler bullets.

Strata having characteristics as mentioned above may r consist of friable material or soft sands that, while easily obtained in the downhole areas of the well bore, are frequently lost through breakup or washout before a side wall sampling projectile may be transported to the earths surface. It is, frequently, the samples from these strata, nearly impossible to obtain by present means, that provide an invaluable source of information on the petroleum crude producing possibilities of the Well bore.

The sample receiving projectile of the present invention is intended to reduce, if not completely eliminate, the loss of side Wall samples from even the most unconsolidated or friable formations by the provision of means for retaining the sample within the projectile in a physical manner and `by the substantial elimination of Washing passages through which a sample may be Washed out of the projectile in its travel to the earths surface. The projectile is further constructed in a manner to provide reduced resistance to the passage of the side wall forma- `tion Vthrough the projectile in the collection of the sample ice and easy removal of the enclosed sample from the side wall formation.

Another object of the present invention is a projectile for use with a side wall sampling device having the provision of improved means for retaining a. sample after it has been obtained from the side wall of a well bore.

Another object of the present invention is a projectile for use with a side Wall :sampling device providing for ease of obtainment of side wall samples from the side wall formations after the forced penetration of the projectile into the formation.

A further object of the present invention is an improved projectile for use with a side wall sampling device for use in the collection of samples from both hard consolidated formations and soft friable formations.

A `further object of the present invention is an improved projectile for use with a side wall sampling device having provision for the easy removal of the collected sample from the projectile with a minimum risk of contamination with material removed from other similar projectiles.

A further object of the present invention is the provision of a resilient sample retaining means Within a projectile employed in the obtaining of side Wall samples of the earth formations penetrated by a Well bore.

Another object of the present invention in accordance with the preceding objects is the provision `of a releasable sample retaining means for engaging the sample collected by the projectile when the projectile is removed from the side wall of a well bore.

Further objects and features of the invention will be readily apparent to those skilled in the art from the speciiication and appended drawings illustrating certain pre- 'ferred embodiments in which:

Fig. l is an elevational view of a side wall core sampler having incorporated therein a plurality of projectiles embodying the invention, and showing the respective positions of the several projectiles as the sampler is transported within the Well 'bore and after one sample has been collected.

Fig. 2 is an elevational view of the projectile of the present invention in its penetrated position within the side Wall of a Well bore.

Fig. 3 is an elevational view in partial section illustrating the projectile of the present invention prior to its penetration into the side wall of a well bore.

Fig. 4 is an exploded perspective view of the projectile of the present invention and illustrating partial sections yof certain of the components.

Fig. 5 is an elevational view in partial section of the projectile of the present invention after a sample has been obtained of a friable, unconsolidated formation.

Fig. 6 is a sectional View taken along vthe lines 6 6 of Fig. 3.

Fig. 7 is a plan view of a projectile head1 of a modified form of the projectile of the present invention.

Fig. 8 is a plan view of a barrel of a modified form of the projectile of the present invention.

Fig. 9 is a sectional view taken generally along the lines 9-9 of Fig. l0 and illustrating the assembled head and barrel of the modified form of the projectile of the present invention with certain parts rotated into interlocking position.

Fig. l0 is a sectional view taken along the lines lilllil of Fig. 9 and illustrating above line A-A the alignment of head and barrel of the modied form of the projectile for assembly into projectile as shown in Fig. 9.

Referring now to Figs. l and 2, the projectile of the present invention is intended `to be forced into the side Wall 11 ot an earth formation l2 penetrated by a Well bore 13. The projectile 14 is supported, in a manner to a, .9 be described, in a composite side wall sampler gun 15 suspended on a cable 16 from the earths surface and 1s intended to be raised and lowered in a fashion conven- =tional `in theart. :[fhe 15 fmay ,contain any lsuitable plurality Vof projectiles I1,4, each being securely xed to .the gun 15 by a flexible wire or leashihg .means .17 having ,sufficient strength .to support lthe projectile 14 and, in a manner to bedeined hereinafter, to retrieve .the projectile from 'its penetrated .position within -the formation 12. Y i I AThey projectile 14 is supported within the sampler gun 15 in a suitable barrel or Vthe like and is accelerated toward the side wall 11 of the well .bore 1:3 in any yof the many manners conventional in ,the `side wall -sampling art, oneof .these being the explosion of a charge be-` hind the projectile 14.

` 4Referring now to 3 wherein the projectile 14 is shown in partial section as constituting a head portion 21 having a charrifered forward end and an interially formed ygroovel 22 giving the head a generally J-shaped configuration. Head portion 21 is positioned in an an- `hular fashion around the end 4of a barrel 23 and, in its normal position, is secured to the barrel by a plurality of pins 24 extending through suitable holes 25 and 26 in the head 21 and barrel 23, respectively. Barrel 23 is provided with a plurality of equally spaced holes 27 rirnming the periphery of the barrel for a purpose to be hereinafter defined. An interior threaded portion 28 of increased diameter 'is provided on barrel 2 3 opposite to the end engagingV head 21V and a pair of axial grooves 29 are formed into the barrel between the threaded portion 2S and ports 27 to provide keyway guides for a part to' be hereinafter defined.

The threaded end of the barrel 23 is enclosed by a cap 31 exterially threaded at 32 for cooperation with the interially threaded portion 28 of the barrel 23 and iaving a groove at 33 to accommodate a rubber sealing ring 3 4. Sealing ring 34 serves to secure the assembled projectile Within the sidewall sampler gun 15. Cap 31, inaddition to performing vthe enclosing duty just defined, also 4provides a surfacefor attachment of the flexible cable17. The cable is secured to an extension 35 and is securely held by a suitable locking nut 36.

The interior of the barrel 23 is adapted to accommodate axially movable sample retaining portions of theV projectiley including a cylinder 37 and a catcher 38. The cylinder 37 is adjacent to the interior surface of the barrel 23 and is provided, lat the end adjacent to the cap 31, with a plurality of cutout portions ,39,7 presenting a crcwnlike appearance to that end of the cylinder. The cutout portions 39 are aligned with the previously mentioned holes 27 annularly spaced around the periphery of the barrel 23.

The catcher 38, while cylindrical in its assembled form, is preferably of a split half-cylindrical formation as shown in Fig. 6 witlia mortise and tenon joint at 40, and each portion is provided with a radially extending rib 41. The ribs 41 of the half sections of the catcher 38 are each provided with a cutout at 42 such that, with the half sections assembled into its cylindrical configuration, the cutouts 42 will be diametrically opposed.- The catcher 3.8 is further provided with an extending key 43 to form, in the assembled cylindrical form, a pair of diametrically opposed keys for cooperation with the axial grooves 29 in the barrel 23, A pair of diametrically opposed flutes ofl the cylinder 37 formed by the cutout portions 39 are provided with extensions 4 4 for cooperation with the cutout portion 4 2 on the rib 41 of the catcher 38. Also provided on the catcher 38 are a comparable plurality of circular cutout portions 45 axially aligned with the cutout portions `27 and 39 of the barrel 23 and cylinder 37, respectively.

The foregoing components and their cooperating portions provide for the positioning of the cylinder 37 'andcatcher 38 within the barrel 23. VThe cooperation of -rel Z3.

the extension 44 of Ithe cylinder 37 with the cutout 42 in the rib 41 of catcher 38 provides for the proper alignment of the cut out portion.39 with the cutouts 45 and insures against rotary movement of the cylinder about the catcher. The cooperation of the extending key 43 with the groove 29 in the barrel 23 insures the proper positioning of the catcher within the barrel to align cutout portions 39 and 45 with cutout portion `27 of the barrel 23. In this manner the barrel, catcher and cylinder are all securely positioned in proper rotational alignment in the assembly in the projectile 14.

One of the important features of the catcher 38 of the present inuention is the provision of a serrated .end adjacent to the head 21. The serrations form a plurality of saw-like teeth 51 that are, in the position as` shown in Fig. 3, retained within the groove 22 in the interior surface of the head 21 and between one surface olf the groove v22 ,and the interior surface `of .the bar- The catcher is Constructed of a re.- silient material and the 'teeth portions 51 have an inherent bias to .close upon themselves to form ,an en- `closed cylindrical .end for the catcher with the teeth 51 being retained against their inherent bias by their posi- 'tion Within .the groove 22 as shown in Fig- 3- The related position of the teeth 151 of the .catcher 3.8 -is .shown in Figure 5 after they have been released from their cooperation within the groove 22 in the head 21.

The operation of the improvement of the present invention is as lfollows: The composite projectile 14 is retained within a barrel, not shown, in the sampler 15 by the cooperation of the sealing ring 34 with the interior surface off the barrel. An explosive charge, or the like, is provided in the sampler 15 behind the projectile 14 for driving the projectile into the side Wall 11 of a Well bore V13 to force a sample of the formation 12 into the interior of the projectile as defined by the catcher 38. The well bore 1 3 at the location of the sampler 15 will, more thanV likely, be filled with drilling mud employed in the drilling operation, As the projectile 14 passes through the drilling mud, the mud will be forced into the UQOI of the projectile and will pass through the pro.- jectile in the passageways provided by hole 45, cutout 39 and hole `27 of the catcher, cylinder and barrel, respectively. When the projectile 14 encounters the formation 12, any additional drill mud within the catcher will be forced through the holes along with, perhaps, a portion of the formation 1,2. The impact vof the projectile against the formation 12 will shear the pins 24 allowing the barrel 2,3 to move further into the groove 22.

The projectile now may be removed from the formation 12 through raising or lowering the sample-r 15; the removal being affected lby pulling the projectile 14 from its sampling position by the cable 17. As the body of projectile is removed from the formation, the head 21 will be left in the formation imbedded therein away from the bore hole 13 and the teeth 51 of the catcher 38 will be removed from the groove 22 of the head 21 .and through their inherent bias, will be permitted to enclose upon a sample within the projectile. Continued movement of the projectile will cause an axial movement of the `c5din'der 37 and catcher 38 with respect to the biarrel 23 as collar 41 moves Within the increased diameter portion at the interior surface of the barrel 23 and key 43 moves along the groove 29 Without interference to the axial movement. As illustrated in Fig. 5, the axial movement will misalign the cutouts 39 and 45 in the cylinder 3,7 and catcher 38, respectively, with the cutout portions 217 of the barrel 23. In this position of misalignment the possibility of washout of the projectile from drilling fluids passing into the projectile is substantally eliminated- The projectile 1,4 Ireceive samples in the manner just Previouslydescribed. regardless 0f whether the formati@ penetrated is of a hardlnsolidated consistency or Whether it is of a sandy, soft or friable condition. If

the formation is hard and consolidated, the teeth 51 of the catcher 38 will be unlikely to collapse into the hemispherical formas illustrated n Fig. 5; on the other hand, if the formation is of a sandy, soft or friable nature, the teeth 51, through their inherent bias, will collapse on the obtained sample so as to substantially enclose the entire end of the projectile as shown in Fig. 5, thereby reducing the possibility of washing the sample out of the projectile. The interior ofthe catcher within the projectile 14 is now substantially sealed from the fluids Within the well bore 13 through the enclosed end portion provided by the resilient teeth 51 and through the misalignment of the cutout portions 27, 39 and 45 of the barrel 23, cylinder 37 and catcher 38, respectively.

It should now be readily apparent with the employment of the projectile of the present invention with a sampling device as conventionally employed in the obtaining of side wall samples of a well bore, that the samples so obtained will be successfully retained the projectile 14 land that the samples will be within the projectile when the sampler has been returned to the earths surface after having performed its sampling run. Through the use of the improved side wall sampler bullet of the present invention, the likelihood of failure of a sampling run is greatly reduced and increased geological information concerning the subsurface formations is made available through the improved condition of the samples so obtained. The split half cylindrical form for the catcher 38 provides the additional facility of allowing easy removal of the sample from the catcher after it has been obtained from the well bore side walls. f

In Figs. 7 through 10 an alternative form for the cooperation between the head and the barrel of a projectile is illustrated. ln these iigures a head 21-A is provided for the barrel 23-A, each being provided with interlocking portions to adapt the projectile of this alternative form for the retention of the head with the projectile as the projectile is removed from the sampled formation. This alternative form is `desirable should there be some objection tothe release of the head in the side wall formations or an objection to the head being dropped to the bottom of the well bore where, in either position, it might interfere with the continued drilling in an enlargement or extension of the well. In the projectile of Fig. 1 through 6 the head portion may be of a drillable material and its release within the well bore is, therefore, not seriously objectionable. Should a head of extremely hard material be desired, there would then be the problem of allowing the head to remain in the formation where it may drop into the bottom of the 'well bore with the eventual possibility of causing damage to a drill bit or an expensive shing operation for its removal from the well bore.

In the alternative form as illustrated, the barrel ZS-A is provided with an extending annular rib 50 and the head Zl-A is provided with an inwardly extending annular rib 52. The rib 50 of the barrel 23-A is formed into a plurality of randomly spaced segments 53 of varying arcuate lengths establishing a plurality of grooves 54 therebetween. The inwardly extending annular rib 52 of the head 21-A is formed with segments 55 and grooves 56 having the same random spacing and being so arranged that the grooves 56 of the head 21-A are complementary in size and arcuate length to the segments 53 of the barrel Z3-A. With the segments and grooves of the head and barrel formed in the manner just described, the head Zl-A may be inserted over the end of the barrel 23-A to assume the general alignment shown in Fig. 9. The inserting alignment for the head and barrel is shown in the section of Fig. l0 above the line designated A-A.

On being assembled in the manner just defined, the head 21-A may be rotated with respect to the barrel 23-A to misalign the randomly spaced segments and grooves of the two components so that the head may not be axially removed from the barrel Z3-A. This mis- `alignment is illustrated below the line A-A of Fig. 10 indicating the cooperation between segments 53 of the |barrel 23-A and segments 55 of the head 21-A. A pin 24-A will cooperate with holes 25-A and 26-A of the head and barrel, respectively, to provide for the secure positioning of the head and `barrel `as in the projectile illustrated in Figs. 1 through 6, and the cooper-ation of the pin with the holes in the respective members will establish the position of rotational alignment between the head and projectile of this alternative form.

In the employment of the projectile of this form in the manner as previously described with respect to the projectile of Figs. l through 6, the pin 24-A will be severed in the same manner; however, even with some rotational movement of the head with respect to the barrel there is an acute unlikelihood that segments and grooves `will ever become so aligned that the barrel may be removed from the formation 12 without carrying the head along with it. The projectile of this alternative form will -be provided with the core catcher and interior cylinder as is illustrated in the projectile of Figs. 1 through 6 and all other components land cooperating portions of the projectile will he the same as is illustrated in those iigures.

While certain preferred embodiments of the invention havelaeen speciiically disclosed, it is understood that the invention is not lirnited thereto, `as many variations will `be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

I claim:

l. A side wall sampler bullet comprising a cylindrical barrel, a removable head portion at one end of said barrel, and a cylindrical catcher member having one end thereof serrated to form a plurality of resilient fingers, said catcher member being positioned |within and in axial alignment with said barrel with said serrated end adjacentto said one end of said barrel, each of said resilient fingers having an inherent bias tending to collapse said fingers toward the axis of said catcher and. being movable against said bias to position said finge-rs` adjacent to said barrel to establish said cylindrical form for said catcher, means on said head portion extending interiorly of said barrel and engaging said resilient fingers to maintain said iingers adjacent to said barrel, and releasable means engaging said head portion and barrel for securing said head portion to said barrel in engaging position with said fingers.

2. The side wall sampler bullet of claim l wherein said cylindrical catcher member consists of two half cylinder portions positioned within said barrel to engage each other along longitudinal edges aligned with the axis of said barrel.

3. A side wall sampler bullet comprising a cylindrical barrel, a head portion at one end of said barrel, a cap portion at the other end of said barrel, and a cylindrical catcher member having one end thereof serrated to form a plurality of resilient fingers, said catcher member being slidably positioned within and in axial alignment with said barrel, with said serrated end adjacent to said one end of said barrel, each of said resilient fingers having an inherent bias tending to collapse said lingers toward the axis of said catcher and being movable against said bias to position said fingers adjacent to said barrel to establish said cylindrical form for said catcher, said barrel and said catcher member being provided with a plurality of circumferentially spaced aligne-d cut-out portions adjacent to said other end of said barrel, means on said head portion extending interiorly of said barrel and catcher and engaging said resilient fingers to maintain said fingers adjacent to said barrel and said cut-out portions in substantial alignment longitudinally of said barrel, and releasable means engaging said head portion and barrel for securing said head portion to said barrel in engaging position with said fingers, whereby release of said releasable means releases said head for movement from said yengaging `position -Withsaid fingers and said catcher -for"movementlongitudinally lo'f said-barrel 'to Inisalignsaicl' c11tout port-ions.

4. JA'sjide Wall Sampler bullet lcomprising a vcylindrical barrel, a removable :head portion at one 'end of said `barrel, a cap portion at "the-other end of said barrel, a tubular member, land a cylindrical ycatcher of tWo half cylinderportions-engaging leach other along longitudinal edgesparallel to the zlongitudinal axis of said catcher, said half cylinder portions being serrated at one end -to form japlurality of resilient fingers, each of said resilient lingers having-an inherent bias tending to collapse said fingers toward the axis of'said catcher and beingmovable against said bias to position saidiingers parallel to said longitudinal axis of said catcher, said tubular member encircling said'catcher and bei-ng releasa'bly secured thereto, said tubular member and catcher being positioned Within and in axialalignmentwith said barrel with said serrated end of said portions adjacent V-to -said 1one end of said barrel, Va plurality of cut-out portions `-throng-h said catcher, tubular `member and barrel circumferentially spaced thereabout and being aligned radially of said barrel adjacent to said other endof said barrel, means on said head portion extending interiorly of said barrel and catcher and engaging said resilient iingers to maintain said iingers parallel to said axis of said catcher and said cut-out portions in substantial lalignment longitudinally of Said barrel, and releasablc means engaging said head portion and barrel for securing said head portion to said barrel in engaging position with said fingers, whereby release of said releas able means releases said head for movement from said engaging position with said fingers and said catcher and tubular member for movement longitudinally of said barrel to misalign said cut-out portions therethrough with said cut-out portions through said barrel.

5. A side Wall sampler bullet comprising a cylindrical barrel, a removable head portion at one end of said barrel, and a cylindrical catcher member having one end thereof serrated to form a plurality of resilient ingers, said catcher member being positioned Within and in Vaxial Valignment `with said"barrel"with said serrated `end ad- -jacent to's'a'id lon'efend'offsaid barrel, each of Said resilient fingers `Yhaving an inherent bias tending'tofcollapse 'said ngers 'toward the axisof said catcher and being movlable `against `said lbias''to position said fingers adjacentto said 4barrel vto establish 'said cylindrical iorm yfor said leatchergm'eans Ionsa'id head portionextending interiorly 'of `said barrel and engaging `said resilient iingers lto maintain said -`fingers adjacent to said barrel, releasable meansengaging Vsaid -head portion and barrel Ifor securin g said 4head portion Lto said barrel 4in engaging kposition with said fingers, and interlocking means on said head member land barrel permitting limited axial movement between said head member and barrel to release said resilient fin-gers Whileretaining said head member -on said barrel.

6. The side wall 4sampler bullet of claim 5 wherein said interlocking means lcomprises a plurality yof random sized and spaced Segments and grooves on said barrel, asimilar plurality of complementary sized and spaced segments and grooves on said head member, said segments on said barrel being l'aligned with grooves on said head member for assembling said head member on said barrel and said segments on said head member and said barrel being engageable to interlock said head member -With said barrel, said head member and said barrel being rotatable with respect to each other in Aassembled position to establish said interlock and to Valign said head for assembly to said barrel.

References Cited in the file of this patent UNITED' STATES PATENTS 1,552,755 Pyron Sept. 8, 1925 2,055,506 Schlumberger Sept. 29, 1936 2,126,684 Humason et al. Aug. 9, 1938 2,288,210 Schlumberger June 3 0, i942 2,709,617 Lang May 31, 1955 2,775,427 -Leone Dec. 25, 1956 Huw. .uw 

